#include using namespace std; typedef signed long long ll; #undef _P #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) //------------------------------------------------------- struct RollingHash { static const ll mo0=1000000007,mo1=1000000009; static ll mul0,mul1; static const ll add0=1000010007, add1=1003333331; static vector pmo[2]; string s; int l; vector hash_[2]; void init(string s) { this->s=s; l=s.size(); int i,j; hash_[0]=hash_[1]=vector(1,0); if(!mul0) mul0=10009+(((ll)&mul0)>>5)%259,mul1=10007+(((ll)&mul1)>>5)%257; if(pmo[0].empty()) pmo[0].push_back(1),pmo[1].push_back(1); FOR(i,l) hash_[0].push_back((hash_[0].back()*mul0+add0+s[i])%mo0); FOR(i,l) hash_[1].push_back((hash_[1].back()*mul1+add1+s[i])%mo1); } /*以下ll版*/ ll hash(int l,int r) { // s[l..r] if(l>r) return 0; while(pmo[0].size() RollingHash::pmo[2]; ll RollingHash::mul0,RollingHash::mul1; int N; string S; ll mo=1000000007; RollingHash rh; ll dp[101010]; void solve() { int i,j,k,l,r,x,y; string s; cin>>S; N=S.size(); rh.init(S); ll ret=1; dp[0]=1; for(i=1;i<=N/2;i++) { FOR(j,i) if(dp[j]) { if(rh.hash(j,i-1)==rh.hash(N-i,N-j-1)) (dp[i]+=dp[j])%=mo; } ret+=dp[i]; } cout<